func Pinger(address *net.IPAddr, timeout time.Duration) error {
var (
c *net.IPConn
err error
)
v6 := address.IP.To4() == nil
if v6 {
c, err = net.DialIP("ip6:ipv6-icmp", nil, address)
} else {
c, err = net.DialIP("ip4:icmp", nil, address)
}
if err != nil {
return err
}
c.SetDeadline(time.Now().Add(timeout))
defer c.Close()
typ := icmpv4EchoRequest
if v6 {
typ = icmpv6EchoRequest
}
xid, xseq := os.Getpid()&0xffff, 1
wb, err := (&icmpMessage{
Type: typ, Code: 0,
Body: &icmpEcho{
ID: xid, Seq: xseq,
Data: bytes.Repeat([]byte("Go Go Gadget Ping!!!"), 3),
},
}).Marshal()
if err != nil {
return err
}
if _, err = c.Write(wb); err != nil {
return err
}
var m *icmpMessage
rb := make([]byte, 20+len(wb))
for {
if _, err = c.Read(rb); err != nil {
return err
}
if !v6 {
rb = ipv4Payload(rb)
}
if m, err = parseICMPMessage(rb); err != nil {
return err
}
switch m.Type {
case icmpv4EchoRequest, icmpv6EchoRequest:
continue
}
break
}
return nil
}
func (p *Pinger) run(once bool) {
p.debugln("Run(): Start")
var conn, conn6 *net.IPConn
if p.hasIPv4 {
if conn = p.listen("ip4:icmp"); conn == nil {
return
}
defer conn.Close()
}
if p.hasIPv6 {
if conn6 = p.listen("ip6:ipv6-icmp"); conn6 == nil {
return
}
defer conn6.Close()
}
recv := make(chan *packet, 1)
recvCtx := newContext()
wg := new(sync.WaitGroup)
p.debugln("Run(): call recvICMP()")
if conn != nil {
wg.Add(1)
go p.recvICMP(conn, recv, recvCtx, wg)
}
if conn6 != nil {
wg.Add(1)
go p.recvICMP(conn6, recv, recvCtx, wg)
}
p.debugln("Run(): call sendICMP()")
queue, err := p.sendICMP(conn, conn6)
ticker := time.NewTicker(p.MaxRTT)
mainloop:
for {
select {
case <-p.ctx.stop:
p.debugln("Run(): <-p.ctx.stop")
break mainloop
case <-recvCtx.done:
p.debugln("Run(): <-recvCtx.done")
p.mu.Lock()
err = recvCtx.err
p.mu.Unlock()
break mainloop
case <-ticker.C:
p.mu.Lock()
handler := p.OnIdle
p.mu.Unlock()
if handler != nil {
handler()
}
if once || err != nil {
break mainloop
}
p.debugln("Run(): call sendICMP()")
queue, err = p.sendICMP(conn, conn6)
case r := <-recv:
p.debugln("Run(): <-recv")
p.procRecv(r, queue)
}
}
ticker.Stop()
p.debugln("Run(): close(recvCtx.stop)")
close(recvCtx.stop)
p.debugln("Run(): wait recvICMP()")
wg.Wait()
p.mu.Lock()
p.ctx.err = err
p.mu.Unlock()
p.debugln("Run(): close(p.ctx.done)")
close(p.ctx.done)
p.debugln("Run(): End")
}